class ParamHistFunc: public RooAbsReal

  _dataVar("!dataVar","data Var", this, (RooRealVar&) var),

 Create the list of RooRealVar
 parameters which represent the
 height of the histogram bins.
 The list 'vars' represents the
 observables (corresponding to histogram bins)
 that these newly created parameters will
 be mapped to. (ie, we create one parameter
 per observable in vars and per bin in each observable)
 Store them in a list using:
 _paramSet.add( createParamSet() );
 This list is stored in the "TH1" index order
 Get the number of bins
 in the nominal histogram

 Create the list of RooRealVar
 parameters which represent the
 height of the histogram bins.
 The list 'vars' represents the
 observables (corresponding to histogram bins)
 that these newly created parameters will
 be mapped to. (ie, we create one parameter
 per observable in vars and per bin in each observable)
 Store them in a list using:
 _paramSet.add( createParamSet() );
 This list is stored in the "TH1" index order
 Get the number of bins
 in the nominal histogram
 We also set the parameters to have nominal min and max values

 Create the list of RooRealVar
 parameters which represent the
 height of the histogram bins.
 Store them in a list
 _paramSet.add( createParamSet() );
 Get the number of bins
 in the nominal histogram

 Advertise that all integrals can be handled internally.

 Implement analytical integrations by doing appropriate weighting from  component integrals
 functions to integrators of components

 Return sampling hint for making curves of (projections) of this function
 as the recursive division strategy of RooCurve cannot deal efficiently
 with the vertical lines that occur in a non-interpolated histogram

 Return sampling hint for making curves of (projections) of this function
 as the recursive division strategy of RooCurve cannot deal efficiently
 with the vertical lines that occur in a non-interpolated histogram